3D Printable Bearings That Actually Work, No CAD Tweaking Required

September 17, 2022 by 22 Comments

3D printing bearings with an FDM printer can be an iffy endeavor, but it doesn’t have to be that way. [Matvey Kukuy]’s Ultimate 608 Bearing with Calibration Kit is everything you’ll need to dial in and print functional 608-style print-in-place bearings on your 3D printer.

Calibration pieces have a handy label attached for identification.

[Matvey] found that there are two key tolerances to get right. And by “get right” he means “empirically determine which works best with your filament and printer”. But don’t worry, there’s no need to get into CAD work to make that happen. [Matvey] has exported a staggering 64 slightly different calibration models (and their matching production versions) along with a printable testing tool. With the help of a step-by-step process that resembles a sort of binary search, one can take the Goldilocks approach to find just the right model for one’s filament and printer in a minimum of steps.

There’s one more tip as well: [Matvey] says that once you determine the best model to use, don’t fill the print bed with copies, unless you want a bed full of possibly non-working bearings! Why is this? A 3D printer prints a bed full of objects slightly differently than it prints a single one, and since the margin for error on the perfectly-selected bearing is so small, that can be enough to keep it from working. To print more than one bearing at a time, position them far from each other and use something like PrusaSlicer’s sequential printing, which is an option to print each object completely before starting the next one.

[Matvey]’s own best results came from printing with PLA at a layer height of 0.16 mm. He also used grease in the bearing to improve performance and extend its life. He doesn’t specify what kind of grease he used, but we’d recommend a plastic-safe grease like PTFE-based Super Lube.

Have you used 3D printed bearings in a project? Would [Matvey]’s design be helpful to you? Let us know all about it in the comments.

Gaze Upon Just How Thin ATM Skimmers Are Getting

September 16, 2022 by 63 Comments

ATM skimmers are electronic devices designed to read financial card information, and they are usually paired with a camera to capture a user’s PIN. These devices always have to hide their presence, and their design has been a bit of an arms race. Skimmers designed to be inserted into a card slot like a parasite have been around for several years, but [Brian Krebs] shows pictures of recently captured skimmer hardware only a fraction of a millimeter thick. And that’s including the battery.

As hardware gets smaller, cameras to capture PIN entry are more easily hidden in things like fake panels.

The goal of these skimmers is to read and log a card’s magnetic strip data. All by itself, that data is not enough to do anything dastardly. That’s why the hardware is complemented by a separate device that captures a user’s PIN as they type it in, and this is usually accomplished with a camera. These are also getting smaller and thinner, which makes them easier to conceal. With a copy of the card’s magnetic strip data and the owner’s PIN, criminals have all they need to create a cloned card that can be used to make withdrawals. (They don’t this so themselves, of course. They coerce or dupe third parties into doing it for them.)

Retrieving data from such skimmers has also led to some cleverness on the part of the criminals. Insertable readers designed to establish a connection to the skimmer and download data is how that gets done. By the way, retrieving data from an installed skimmer is also something criminals don’t do themselves, so that data is encrypted. After all, it just wouldn’t do to have an intermediary getting ideas about using that data for their own purposes. Continue reading “Gaze Upon Just How Thin ATM Skimmers Are Getting” →

Scratch-Built RC Excavator Is A Model Making Tour De Force

September 16, 2022 by 20 Comments

Some projects just take your breath away with their level of attention to detail. This scratch-built RC-controlled model excavator is not only breathtaking in its detail, but also amazing for the materials and tools used to create it.

We’ve got to be honest, we’ve been keeping an eye on the progress [Vang Hà] has been making on this build for a few weeks now. The first video below is a full tour of the finished project, which is painstakingly faithful to the original, a Caterpiller 390F tracked excavator. As impressive as that is, though, you’ve got to check out the build process that starts with fabricating the tracks in the second video below. The raw material for most of the model is plain gray PVC pipe, which is sliced and diced into flat sheets, cut into tiny pieces using a jury-rigged table saw, and heat formed to create curved pieces. Check out the full playlist for a bounty of fabrication delights, like tiny hinges and working latches.

We can’t possibly heap enough praise onto [Vang Hà] for his craftsmanship, but that’s not all we love about this one. There are tons of helpful tips here, and plenty of food for thought for more practical builds. We’re thinking about that full set of working hydraulic cylinders that operates the boom, the dipper, and the bucket, as well as the servo-operated hydraulic control valves. All of it is made from scratch, of course, and mostly from PVC. Keep that in mind for a project where electric motors or linear actuators just won’t fill the bill.

If this construction technique seems familiar to you, it could because we featured a toolbox made out of similarly processed PVC pipes back in June.

Continue reading “Scratch-Built RC Excavator Is A Model Making Tour De Force” →

A Pill Dispenser For The Person With Everything

September 16, 2022 by 15 Comments

Sorting out pills is a mildly tedious task, and one that’s ripe for a bit of automation. It’s a task that [Mellow] has taken on enthusiastically, with the result of an extremely well-designed dispenser that has a stack of hoppers with servos controlled by an ESP8266 that dispense the pills required on time.

There are a series of videos of which we’ve put the latest below the break, showing the various iterations of this project. Earlier versions used multiple microcontrollers rather than the single ESP, and his sensor choice is both simple and ingenious. A single vibration sensor detects the pills falling upon it, resulting on an extremely compact electronics set-up and the base of the 3D printed stack.

We’re struck by this design, by its simplicity, ingenuity, and its pleasing aesthetics with the use of a piece of perfboard and a load of heatshrink to make an extremely tidy wiring loom. We’re not sure we’ll ever need a pill dispenser like it, but if we did we don’t think we could come up with a better design.

You might be surprised to find that pill dispensers have appeared here before.

Continue reading “A Pill Dispenser For The Person With Everything” →

This Week In Security: 11,000 Gas Stations, TrustZone Hacks Kernel, And Unexpected Fuzzing Finds

September 16, 2022 by 6 Comments

Automated Tank Gauges (ATGs) are nifty bits of tech, sitting unseen in just about every gas station. They keep track of fuel levels, temperature, and other bits of information, and sometimes get tied into the automated systems at the station. The problem, is that a bunch of these devices are listening to port 10001 on the Internet, and some of them appear to be misconfigured. How many? Let’s start with the easier question, how many IPs have port 10001 open? Masscan is one of the best tools for this, and [RoseSecurity] found over 85,000 listening devices. An open port is just the start. How many of those respond to connections with the string In-Tank Inventory Reports? Shodan reports 11,113 IPs as of August of this year. [RoseSecurity] wrote a simple Python script that checked each of those listening IPs came up with a matching number of devices. The scary bit is that this check was done by sending a Get In-Tank Inventory Report command, and checking for a good response. It seems like that’s 11K systems, connected to the internet, with no authentication. What could possibly go wrong? Continue reading “This Week In Security: 11,000 Gas Stations, TrustZone Hacks Kernel, And Unexpected Fuzzing Finds” →

A graphing calculator with a 3D-printed enclosure, with a circuit board next to it

2022 Cyberdeck Contest: The Galdeano Is More Than A Graphing Calculator

September 15, 2022 by 14 Comments

Graphing calculators have evolved from expensive playthings for rich nerds to everyday tools for high schoolers worldwide. Even though teenagers nowadays carry powerful internet-connected computers in their pockets, math teachers often prefer them to use a clunky Z80-powered calculator in class, if only because their limited performance reduces the potential for distraction. The worst thing a lazy student can do is play a simple game like Snake or Tetris.

But what if you’re not a student anymore and you want a graphing calculator that has up-to-date hardware and infinite customizability in software? Look no further than [Angel Cabello]’s Galdeano, a handheld that has all the features of a modern graphing calculator plus a lot more. The heart of the device is an ESP32, which sits on a custom PCB that also holds a 6×7 array of push-buttons and a 320×240 touch-sensitive color display. It can be powered through a lithium-polymer battery or, like a classic calculator, through four AAA cells. The entire thing is housed in a 3D printed enclosure with color-coded buttons indicating various built-in functions.

The ESP32 runs MicroPython along with a symbolic math engine called Eigenmath. This enables the Galdeano to  manipulate expressions, perform integration and differentiation, and plot functions. Porting Eigenmath to a memory-constrained platform like the ESP32 was quite a challenge and required a few workarounds, including a memory partition scheme and even a custom compact font with mathematical symbols.

Thanks to the flexibility of MicroPython and the ESP’s WiFi system, the Galdeano is not limited to implementing a calculator: it can also perform various general-purpose tasks ranging from file editing to controlling a set of smart light bulbs. The project page doesn’t mention any games yet, but we’re sure it won’t take long before someone ports Tetris to this system as well.

Of course, even classroom-grade calculators can be pushed to do much more than their designers intended: they can receive GPS signals, run Debian or even perform ray tracing. If you’re looking for a powerful open-source calculator, this BeagleBoard-based machine runs the R statistical computing environment.

Continue reading “2022 Cyberdeck Contest: The Galdeano Is More Than A Graphing Calculator” →

Fork And Run: The Definitive Guide To Getting Started With Multiprocessing

September 15, 2022 by 23 Comments

Since the early 2000s, the CPU industry has shifted from raw clock speed to core counts. Pat Gelsinger famously took the stage in 2002 and gave the talk the industry needed, stating processors needed specialty silicon or multiple cores to reduce power requirements and spread heat. A few years later, the Core series was introduced with two or four-core configurations to compete with the AMD Athlon 64 x2.

Nowadays, we’re seeing heterogeneous chip designs with big and little cores, chiplets, and other crazy fabrication techniques that are fundamentally the same concept: spread the thermal load across multiple pieces of silicon. This writer is willing to put good money into betting that you’ll see consumer desktop machines with 32 physical cores in less than five years. It might be hard to believe, but a 2013 Intel Haswell i7 came with just four cores compared to the twenty you’ll get in an i7 today. Even an ESP32 has two cores with support in FreeRTOS for pinning tasks to different cores. With so many cores, how to even write software for that? What’s the difference between processes and threads? How does this all work in straight vanilla C98?

Continue reading “Fork And Run: The Definitive Guide To Getting Started With Multiprocessing” →